Agave Sierra Negra is a wild sub varietal of the agave Americana family. It takes up to 25 years to mature. Today, mezcal made with agave Sierra Negra is quite rare. It was widely cultivated many years ago but due to over-production and long times to mature it has been mostly abandoned in favor of agave Espadín, which can be easily farm-grown and cultivated. Depending on the region, the term Sierra Negra may actually be referring to Arroqueno, which is very similar in size, shape, and character.